Round baler and method for operating a round baler

Abstract

A round baler and a method for operating a round baler are disclosed. The round baler has a variable diameter and is bounded by an endlessly rotating pressing means. The pressing means is guided by a plurality of rollers, wherein a loop of the pressing means is guided by a first clamping arm mounted on the housing side and by a second clamping arm mounted on the housing side. The first and second clamping arms are adjusted by actuators so that at least one compaction pressure is generated with which the pressing means acts to form a round bale. A control unit automatically controls the actuators depending on a compaction power curve, accounting for operating parameters and/or environmental parameters of the round baler, thereby maintaining a substantially stable operating point during the shaping process, in which the required compaction power and the available drive power are substantially equal.

The invention claimed is: 
     
         1 . A method for operating a round baler, the method comprising:
 operating the round baler, the round baler comprising a baling chamber having a variable diameter and positioned in a housing, the baling chamber being bounded by a rotating pressing device, wherein the pressing device is one or both of driven or guided by a plurality of rollers, wherein a loop of the pressing device is guided by a first clamping arm which is pivotably mounted on a side of the housing and includes one or more rollers on a side of the baling chamber, wherein the pressing device is guided by a second clamping arm which is pivotably mounted on the side of the housing and has at least one roller on a free end, wherein one or more hydraulically-actuated actuators adjust the first clamping arm and the second clamping arm so that at least one compaction pressure is generated with which the pressing device acts to form a round bale;   accessing, by a control unit, at least one compaction power curve;   accessing, by the control unit, one or both of one or more operating parameters or one or more environmental parameters; and   automatically controlling, by the control unit using the at least one compaction power curve, the one or more hydraulically-actuated actuators to adjust at least one of the first clamping arm or the second clamping arm, by taking into account the one or more operating parameters that affect one or both of the at least one compaction power curve or the one or more environmental parameters of the round baler in order to maintain a substantially stable operating point during a shaping process of the round bale in which compaction power and drive power are substantially equal.   
     
     
         2 . The method of  claim 1 , further comprising:
 inputting, via an input/output unit of the control unit, one or more input variables specified by an operator; and   selecting the compaction power curve to access from a plurality of compaction power curves correlated to different input values that stored in a memory unit accessible by the control unit.   
     
     
         3 . The method of  claim 2 , wherein the one or more input variables specified by the operator are a harvested material type, a bale shape, bale diameters and absolute or relative values for compaction pressures. 
     
     
         4 . The method of  claim 2 , wherein the plurality of compaction power curves accessible by the control unit are used to control the one or more actuators in order to adjust force ratios of the first clamping arm and the second clamping arm. 
     
     
         5 . The method of  claim 2 , wherein the one or more input variables are used to determine a target compaction pressure depending on a current diameter of the bale based on one or more rules. 
     
     
         6 . The method of  claim 1 , wherein automatically controlling the one or more hydraulically-actuated actuators comprises dynamically applying, using the one or more actuators, one or more forces to the first clamping arm and the second clamping arm taking into account the one or both of the one or more operating parameters or the one or more environmental parameters. 
     
     
         7 . The method of  claim 1 , wherein working pressures of the one or more actuators of each of the first clamping arm and the second clamping arm are monitored by a respective pressure relief valve. 
     
     
         8 . The method of  claim 1 , further comprising monitoring, by the control unit, occurrence of slippage. 
     
     
         9 . The method of  claim 8 , wherein the control unit automatically reduces the compaction power responsive to the control unit determining that a slip limit value is reached. 
     
     
         10 . The method of  claim 9 , further comprising automatically outputting, by the control unit, a warning to the operator responsive to the control unit determining that a slip limit value is reached. 
     
     
         11 . A round baler comprising:
 a baling chamber positioned in a housing and having a variable diameter;   a rotating pressing device configured to bound the baling chamber, the pressing device including one or more rollers configured to perform one or both of drive or guide the pressing device, with a first clamping arm pivotably mounted on a side of the housing and including at least one of the one or more rollers on a bailing chamber side for guiding a loop, and with a second clamping arm pivotably mounted on the side of the housing and having at least one roller at a free end that is configured to guide the pressing device;   one or more hydraulically-actuated actuators configured to adjust a position of the first clamping arm and the second clamping arm in order for the first clamping arm and the second clamping arm to generate a compaction pressure with which the pressing device is configured to form a round bale; and   a control unit in communication with the one or more hydraulically-actuated actuators and configured to:
 access at least one compaction power curve; 
 access one or both of one or more operating parameters or one or more environmental parameters; and 
 automatically control, using the at least one compaction power curve, the one or more hydraulically-actuated actuators to adjust at least one of the first clamping arm or the second clamping arm, by taking into account the one or more operating parameters that affect one or both of the at least one compaction power curve or the one or more environmental parameters of the round baler in order to maintain a substantially stable operating point during a shaping process of the round bale in which compaction power and drive power are substantially equal. 
   
     
     
         12 . The round baler of  claim 11 , further comprising an input-output unit configured to input one or more input variables by an operator. 
     
     
         13 . The round baler of  claim 12 , wherein the input-output unit is configured to input a harvested material type, bale shape, bale diameter, and absolute or relative values for compaction pressures as input variables. 
     
     
         14 . The round baler of  claim 12 , wherein the control unit is further configured to select, based on the one or more input variables input, the compaction power curve from a plurality of compaction power curves correlated to different input values that stored in a memory unit accessible by the control unit. 
     
     
         15 . The round baler of  claim 11 , further comprising one or more sensor devices configured to generate data indicative of one or more of moisture content of collected harvested material, feed quantity collected, or feed quantity fed to the baling chamber. 
     
     
         16 . The round baler of  claim 11 , wherein the control unit is further configured to automatically control the one or more hydraulically-actuated actuators by dynamically controlling, using the one or more actuators, one or more forces to the first clamping arm and the second clamping arm taking into account the one or both of the one or more operating parameters or the one or more environmental parameters. 
     
     
         17 . The round baler of  claim 11 , further comprising a first pressure relief valve configured to set pressure applied by the first clamping arm and a second pressure relief valve configured to set pressure applied by the second clamping arm. 
     
     
         18 . The round baler of  claim 17 , wherein the control unit is configured to set values for each of the first pressure relief valve and the second pressure relief valve in order balance force between the first clamping arm and the second clamping arm. 
     
     
         19 . The round baler of  claim 11 , wherein the control unit is further configured to:
 monitor, by the control unit, occurrence of slippage; and   automatically reduce the compaction power responsive to the control unit determining that a slip limit value is reached.   
     
     
         20 . The round baler of  claim 19 , wherein the control unit is further configured to: automatically output a warning to the operator responsive to the control unit determining that a slip limit value is reached.